This patent relates to a safety cap to be placed over the nozzle of a fluid-dispensing cartridge. More particularly, this patent relates to a safety cap to be placed over the dispensing fitment of an ink cartridge of the type used in automatic lithographic printing presses.
Modern ink cartridges for printing presses typically comprise a hollow tubular body, a moveable plunger inserted into one end, and a stationary dispensing fitment attached to the opposite end. The dispensing fitment covers the dispensing end of the tubular body and has a built-in nozzle for opening and closing the cartridge. Ink is extruded through the nozzle when the plunger is forced toward the dispensing end either manually or, more commonly, by pneumatic pressure. Typically, the cartridge is filled with ink by placing the cartridge with the dispensing end down, adding the ink through the open plunger end, then inserting the plunger. It is also desirable to ship and store ink cartridges with the dispensing end down.
The dispensing fitment is mounted in sealing engagement within the dispensing (top) end of the tubular body and comprises a covering portion and a nozzle extending from the covering portion. The nozzle serves several functions: (1) it guides the flow of ink from the cartridge when the plunger is activated; (2) it prevents the flow of ink at all other times, including during filling, transportation, storage, and installation of the cartridge on the printing press; and (3) it prevents the introduction of air into the cartridge.
A potential problem with conventional ink cartridges is that, during use, the nozzles can leak ink onto the outside of the dispensing fitment. The ink can then dry and flake off, contaminating the ink reservoir beneath the cartridge.
Another potential problem with conventional ink cartridges is that, because of the protruding nozzles, they cannot be stood on their dispensing end for filling, shipping or storage purposes without using a nest or fixture to keep the cartridge upright and stable.
Another potential problem with conventional ink cartridges is the introduction of air into the cartridge. If an ink cartridge is stored or shipped with the dispensing end up, the ink can shift down due to gravity. If the seal on the dispensing nozzle is not airtight, this shifting can pull air into the cartridge and cause the ink to start curing. Curing reduces the quality of the ink and increases the risk of poor quality dispensing.
Thus it is an object of the present invention to provide a safety cap for use with ink cartridges that prevents the flow of ink past the dispensing nozzle seal.
Another object of the present invention is to provide a safety cap that prevents the flow of ink outside the cap if the ink escapes past the dispensing nozzle seal.
Still another object of the invention is to provide a safety cap that enables an ink cartridge to be set upright with the dispensing end down without the need for a nest or fixture to help support the cartridge.
Another object of the invention is to provide a safety cap that keeps the dispensing nozzle clean and protects it from damage during shipping and handling.
Further and additional objects will appear from the description and accompanying drawings.
The present invention is a safety cap for use with ink cartridges of the type having a nozzle extending from a dispensing fitment affixed to the dispensing end. The safety cap prevents the flow of ink out of the cartridge or, if ink escapes past the dispensing nozzle seal, prevents the flow of ink outside the cap. The cap also enables the ink cartridge to be set upright with the dispensing end down without the need for a nest or fixture to help support the cartridge.
The cap comprises a hub portion, a substantially cylindrical outer wall surrounding the hub portion, and an annular wall connecting the hub portion to the outer wall. The hub portion is configured to fit closely over the dispensing fitment nozzle and comprises a dome-shaped top wall and a downwardly extending skirt portion terminating in a sealing lip. The sealing lip is adapted to form a seal with the dispensing fitment when the safety cap in installed onto the dispensing fitment. The outer wall of the cap has a top rim upon which the cartridge can stand during filling, storage and transportation. The skirt portion of the hub has inwardly extending locking elements adapted to be engaged by and disengaged from complementary locking elements on the dispensing fitment.